I'm curious what the difference is between overriding a table's modifiedField method versus overriding the update method.
In our case, we are working on switching the field datatype on a table. Since we cannot just change the data type of the field, we make a second field, and copy the information from the first into the second. Eventually, we update all the UI elements (forms and reports namely) to point to the new field, and then remove the old field. To help with copying the information from one field to another, we have been overriding the update method on the table to copy the value from the first field to the second.
I know this would probably be easier to maintain using the modifiedField method, but I'm curious if there are any significant differences (performance, missed updates, etc) by using the update method instead.
The main difference is that the code in modifiedField method is executed without writing into the Database. This way you can change the value of field2, but if a user close the form without saving the record then no updates will be in the DB. While using an update method you certainly write the changes.
Related
I'm trying to find a way to save a new object if one like it doesn't already exist with a specified custom ID.
I basically need to refresh a whole bunch of data every day but each item has its own ID set somewhere else (so not a parse objectId). I therefore can't use something like the standard save function as it'll just make a new record every time.
I've thought of trying to set the objectId of an object when its first created in the DB but I can't seem to do that... (Half expected this).
I've also thought of doing the obvious - checking if an object exists using a normal query but with a few thousand objects to compare, this will be very inefficient.
Any suggestions?
Maybe there is a save function or variation where its kind of "save or create depending if an object exists with this value in this field" :)
Thank you!
PS. I'm writing this within a Cloud Job - so JavaScript
I know you can soft delete in Doctrine (i.e. do not delete a record but rather add a "deleted" value). There's an extension for that.
Now I wonder if there's a way to "soft update" a record. I mean not actually update the record but rather create a new record and make the old one invalid. In the same extension as soft-delete, there's a function loggable, but this one logs to a different table.
I could create a controller that, instead of updating, soft-deletes
(and thus invalidates) the old record, and then creates a new one
with the new values. But I'm unsure if this is a good practice.
Maybe I should create this action on the object itself? But I'm
unsure how to do this.
Edit
I've looked into Versionable and EntityAudit (as suggested by Tomas), but it seems these bundles do way too much. I merely want to check if a given field is different from the old one, and if not: soft-delete the old one (I'm using softDeleteable so a simple remove() will do); then create a new one with the changed values.
So ideally it would lurk in the shadows until an update is performed. Then read from the mapping configuration which fields it needs to watch, and if these fields are indeed different from what's persisted, the program should execute the remove() and persist() commands.
This extension might suit your use case:
simplethings/EntityAudit
It records any changes you want to track.
So it should be pretty easy to modify it to meed your needs.
I have a changefeed that works fine until I use the pluck() projection. If I use pluck, it doesn't pick up changes form inserts and deletes in my followers embedded collection.
r.table('users')
.getAll(name, {index: 'followers'})
//.without('password', 'phone')
.pluck('name', 'online') // using pluck doesn't pick up changes in insert/delete from followers
.changes({includeInitial:true});
I could use the without command but that seems more error prone as I would have to keep updating that list anytime I added fields to the user object.
Updates to user's online property gets picked up in the changefeed in either scenario.
Why does pluck not show changes to the followers set/collection property?
I'm not 100% sure, but I think this is because when you add the .pluck('name', 'online') to the end, and then you update the followers array, the changefeed logic applies the pluck and then compares the old value to the new value, and since neither of the plucked fields changed it decides that it's a "trivial" change and drops it. (In general ignoring trivial changes is what you want, since one of the main goals of .pluck.changes is to only be notified when the specified fields change.)
I think this probably isn't the desired behavior, though: it's probably more useful to only drop trivial changes if they don't cause the row to enter or exit the subscribed range. I opened https://github.com/rethinkdb/rethinkdb/issues/5205 to track that change.
This isn't supported right now. Check this ticket and this.
I have an custom entity which needs to have a case number for an XRM Application, can I generate a case number from the Service -> Case.
If this is not possible, how can I do this with a plugin, I've looked at the crmnumbering.codeplex.com but this doesn't support 2011, anybody outthere have a solution or should I rewrite it myself?
thanks
I've ran into this same type of issue (I need a custom # for an entity). Here's how you can do it:
Create an Entity called "Counter"
Add a field called "new_customnumber", make it a string or a number depending on what you want
Create a new record for that entity with whatever you want in the new_customnumber field (let's say "10000")
Create a plugin (EntityNumberGenerator) that goes out and grabs that record (you'll probably want to set the security on this record/entity really tight so no one can mess with the numbers)
On Create of the "custom entity" fire the plugin. Grab the value in new_customnumber save it to the "custom entity" (let's say in a "case" field) increment the new_customnumber and save it to the Counter entity.
Warning, I'm not sure how this is with concurrency. Meaning I'm not sure if 2 custom entities being created at the same time can grab the same number (I haven't ran into an issue yet). I haven't figured out a way to "lock" a field I've retrieved in a plugin (I'm not sure it's possible).
You will be unable to create a custom number for custom entities from the normal area you set a case number.
Look at the CRM2011sdk\sdk\samplecode\cs\plug-ins\accountnumberplugin.cs plugin. It's really similar to what you want.
Ry
I haven't seen one for 2011 yet. Probably easiest to write it yourself.
I've always created a database with a table with a single column which is an IDENTITY column. Write an SP to insert, save the IDENTITY value to a variable, and DELETE the row all within a transaction. Return the variable. Makes for a quick and easy plug-in and this takes care of any concurrency issues.
The performance is fast and the impact to your SQL server is minimal.
I am using Sql tables without rowversion or timestamp. However, I need to use Linq to update certain values in the table. Since Linq cannot know which values to update, I am using a second DataContext to retrieve the current object from database and use both the database and the actual object as Input for the Attach method like so:
Public Sub SaveCustomer(ByVal cust As Customer)
Using dc As New AppDataContext()
If (cust.Id > 0) Then
Dim tempCust As Customer = Nothing
Using dc2 As New AppDataContext()
tempCust = dc2.Customers.Single(Function(c) c.Id = cust.Id)
End Using
dc.Customers.Attach(cust, tempCust)
Else
dc.Customers.InsertOnSubmit(cust)
End If
dc.SubmitChanges()
End Using
End Sub
While this does work, I have a problem though: I am also using StoredProcedures to update some fields of Customer at certain times. Now imagine the following workflow:
Get customer from database
Set a customer field to a new value
Use a stored procedure to update another customer field
Call SaveCustomer
What happens now, is, that the SaveCustomer method retrieves the current object from the database which does not contain the value set in code, but DOES contain the value set by the stored procedure. When attaching this with the actual object and then submit, it will update the value set in code also in the database and ... tadaaaa... set the other one to NULL, since the actual object does not contain the changed made by the stored procedure.
Was that understandable?
Is there any best practice to solve this problem?
If you make changes behind the back of the ORM, and don't use concurrency checking - then you are going to have problems. You don't show what you did in step "3", but IMO you should update the object model to reflect these changes, perhaps using OUTPUT TSQL paramaters. Or; stick to object-oriented.
Of course, doing anything without concurrency checking is a good way to lose data - so my preferred option is simply "add a rowversion". Otherwise, you could perhaps read the updated object out and merge things... somehow guessing what the right data is...
If you're going to disconnect your object from one context and use another one for the update, you need to either retain the original object, use a row version, or implement some sort of hashing routine in your database and retain the hash as part of your object. Of these, I highly recommend the Rowversion option as well. Using the current value as the original value like you are trying to do is only asking for concurrency problems.